A long time ago, of troy twice mentioned, but apparently never found the origin of the term
"bain marie". I stumbled on it today in "engines of our ingenuity". It's in the last lines of:

The great chemist Maria the Jewess has been
pretty well lost in the blur of ancient history. Most
of what we know about her comes from the Egyptian
alchemist Zosimos, who wrote in the late days of the
Roman empire, 500 years after Maria lived. Among
other things, Zosimos talks about her invention of the
kerotakis.

Maria invented many types of stills and reflux
condensers. The kerotakis device was one in which
she could boil mercury or sulfur and use its
condensing vapor to heat copper or lead in a pan
above. It was a kind of high-temperature double
boiler.

Remember how a double boiler works: It has an
upper pan where you cook food, nested in a lower
pan of boiling water. The food stays at the same
temperature as the steam condensing under it -- 100
degrees C. And so the one reference to Maria in the
modern world is the French word for a double
boiler. They call it a bain-marie -- Maria's bath.

Mmmmm....nothin' like breathin' that good ol' vapor of mercury to guarantee clear thinking and a long life!

Dear WO'N: I too wondered how she escaped instant mercury poisoning, especially
since her pots were unlikely to fit snugly.

Dear Dr. Bill: Incredibly there were legions of alchemists who worked extensively with mercury and lead in various forms (remember, the transmutation of lead to gold was a major goal of alchemy), and it seems they all labored merrily away for extended periods of time. In fact, drawings of the old experimenting alchemist with a long grey beard are stereotypical. But I wonder how long the average tenure of the occupation was, from the time they started experimenting until the heavy metals got to them in one way or the other...5 years, 10 years? less, more? Hmmm...there's a little trinket of data that you could research, Dr. Bill...must be available somewhere.

We can start in the nineteenth century: the Mad Hatter from Through the Looking Glass was a caricature of a victim of mercury poisoning. Hat-makers used a lot of felt, and felt was manufactured with mercury, and so "mad as a hatter" was a very common - and thoroughly appropriate - simile at the time...

A lady professor of chemistry at Dartmouth died months after spilling a small amount
of dimethyl mercury on her glove. The URL is not so good as the one I saw a while back.
http://www.whale.to/v/merc.html

... and those of us who incorporate a lot of fish into our diets have to be very careful:

http://discover.npr.org/features/feature.jhtml?wfId=841945

"

Spain was among the first nations to
mine the liquid metal known as
quicksilver. "

I do not believe that mercury is mined as the liquid metal. It is mined as cinnabar
a bright orange ore that is however very readily converted into the metal. I have
done it.

I have done it.

Well, that explains a lot!